<template>
  <div class="home-page">
    <div class="banner">
      <div class="container">
        <h1 class="logo-font">conduit</h1>
        <p>A place to share your knowledge.</p>
      </div>
    </div>

    <div class="container page">
      <div class="row">
        <div class="col-md-9">
          <div class="feed-toggle">
            <ul class="nav nav-pills outline-active">
              <li class="nav-item" v-if="user">
                <nuxt-link
                  class="nav-link"
                  :to="{ name: 'home', query: { tab: 'your_feed' } }"
                  :class="{ acitve: tab === 'your_feed' }"
                  exact
                >
                  Your Feed
                </nuxt-link>
              </li>
              <li class="nav-item">
                <nuxt-link class="nav-link" :to="{ name: 'home' }" :class="{ acitve: tab === 'global_feed' }" exact>
                  Global Feed
                </nuxt-link>
              </li>
              <li class="nav-item" v-if="tag">
                <nuxt-link
                  class="nav-link"
                  :to="{ name: 'home', query: { tab: 'tag', tag: tag } }"
                  :class="{ acitve: tab === 'global_feed' }"
                >
                  # {{ tag }}
                </nuxt-link>
              </li>
            </ul>
          </div>

          <div class="article-preview" v-for="article in articles" :key="article.slug">
            <div class="article-meta">
              <nuxt-link class="author" :to="{ name: 'profile', params: { username: article.author.username } }">
                <img :src="article.author.image" />
              </nuxt-link>
              <div class="info">
                <nuxt-link class="author" to="">{{ article.author.username }}</nuxt-link>
                <span class="date">{{ article.createdAt | date('MMM DD,YYYY') }}</span>
              </div>
              <button
                class="btn btn-outline-primary btn-sm pull-xs-right"
                :class="{ active: article.favorited }"
                @click="onFavorite(article)"
                :disabled="article.favoriteDisable"
              >
                <i class="ion-heart"></i>
                {{ article.favoritesCount }}
              </button>
            </div>
            <nuxt-link :to="{ name: 'article', params: { slug: article.slug } }" class="preview-link">
              <h1>{{ article.title }}</h1>
              <p>{{ article.description }}</p>
              <span>Read more...</span>
            </nuxt-link>
          </div>
        </div>

        <nav>
          <ul class="pagination">
            <li class="page-item" v-for="item in totalPage" :key="item" :class="{ active: item === page }">
              <nuxt-link
                class="page-link"
                :to="{ name: 'home', query: { page: item, tag: $route.query.tag, tab: tab } }"
              >
                {{ item }}
              </nuxt-link>
            </li>
          </ul>
        </nav>

        <div class=" col-md-3">
          <div class="sidebar">
            <p>Popular Tags</p>
            <div class="tag-list">
              <nuxt-link
                :to="{ name: 'home', query: { tag: item, tab: 'tag' } }"
                class="tag-pill tag-default"
                v-for="item in tags"
                :key="item"
              >
                {{ item }}
              </nuxt-link>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { getArticles, getYourFeedArticles, addFavorite, deleteFavorite } from '@/api/article';
import { getTags } from '@/api/tag';
import { mapState } from 'vuex';

export default {
  name: 'HomeIndex',
  // 根据需要来决定在那里请求文章列表
  // 如果需要首屏渲染优化或 SEO 抓取，那么写在 asyncData 里
  async asyncData({ query }) {
    const page = Number.parseInt(query.page || 1);
    const limit = 20;
    const tab = query.tab || 'global_feed';
    const tag = query.tag;
    const loadArticles = tab === 'global_feed' ? getArticles : getYourFeedArticles;

    const [articlesRes, tagRes] = await Promise.all([
      loadArticles({
        limit,
        offset: (page - 1) * limit,
        tag: query.tag,
      }),
      getTags(),
    ]);

    const { articles, articlesCount } = articlesRes.data;
    const { tags } = tagRes.data;

    articles.forEach(article => (article.favoriteDisable = false));

    return {
      articles,
      articlesCount,
      limit,
      page,
      tags,
      tab,
      tag,
    };
  },
  watchQuery: ['page', 'tag', 'tab'],
  computed: {
    ...mapState(['user']),
    totalPage() {
      return Math.ceil(this.articlesCount / this.limit);
    },
  },
  methods: {
    async onFavorite(article) {
      if (article.favorited) {
        article.favoriteDisable = true;
        // 取消点赞
        await deleteFavorite(article.slug);
        article.favorited = false;
        article.articlesCount += -1;
      } else {
        // 添加点赞
        await addFavorite(article.slug);
        article.favorited = true;
        article.articlesCount += 1;
      }
      article.favoriteDisable = false;
    },
  },
};
</script>

<style></style>
